But with a deadline looming, the campaign apparently did not feel comfortable letting the DNC off the legal hook.

“The parties continue to engage in cooperative discussions in their efforts to resolve the pending litigation,” Garvey Schubert Barer, a lawyer for Bernie 2016 Inc., said in a status update to the federal court in the District of Columbia. But he said given the deadline imposed by the courts for closing the case, they went ahead and served notice “simply in order to preserve the status quo.”

“We continue to have productive discussions with the Sanders campaign and look forward to resolving this matter,” said DNC spokesman Mark Paustenbach.

The DNC cut off Mr. Sanders‘ access to the party’s voter files in December after accusing one of his campaign operatives of exploiting a loophole to gain access to the files of Hillary Clinton, Mr. Sanders‘ competitor for Democrats’ presidential nomination.

Mr. Sanders said he fired the employee responsible, but said the DNC was treating him unfairly in cutting of his access to the files in the weeks before the first voting.

Mr. Sanders‘ campaign also said the contract he had with the DNC didn’t allow for access to be suspended without proper notice, which they said the DNC didn’t give.